Criminal to Cop
by Nessie Carlie Salvatore
Summary: Stefan Salvatore is a police detective, trying to catch murderer Klaus. He isn't having any luck so his boss gives him a helping hand. Klaus's ex partner. AH/AU Dathrine, Stelena, and Forewood. bad summary. Could use help with a better title.
1. Chapter 1

Detective Stefan Salvatore came into the Mystic Falls Police Station, unshaven and tired.

"Good morning, Stefan." His partner, Tyler Lockwood, said. "You look like hell."

"I feel like hell. Coffee?" Tyler handed a cup over.

"Another all-nighter?" Stefan nodded. "Well, it's about to get worse. Boss wants to see you in his office. Now." Stefan sighed but

went to his boss's office anyway.

"Mr. Saltzman?" He asked, knocking on the door. Alaric looked up and gestured him in.

"Take a seat, Salvatore." He did and Alaric tossed a newspaper on the desk. "He killed another one." Stefan picked the paper up and read the headline 'KILLER STRIKES AGAIN!'

"Klaus?" He asked, not bothering to read the article. Alaric nodded.

"He killed Vicki Donovan and dumped her body in the park, same as all the others."

"Rape?"

"No, she consented." Alaric stood and began to pace around his office. "I wanted to ask- well tell you something."

"What, sir?"

"The senator wants Klaus in custody, or dead, now."

"I know that."

"So, he's decided to give a helping hand, so to speak."

"I don't understand." Alaric sighed.

"You're to go the Virgina State Penitentiary and find out what it would take to get help from Klaus's ex-partner."

"You mean..?" Alaric nodded.

"He asked for you specifically."

"No."

This isn't up for negotiation!" Alaric slammed his hand down on the desk, any trace of friendliness gone. "You go down there, find out what he wants. We need him Stefan." Stefan sighed but nodded and got up to leave. "He's already waiting for you." Alaric said as he walked out.

An hour long drive later, Stefan walked into the interrogation room of the prison and meet a pair of sparkling blue eyes.

"I can't believe they actually sent you." The man said, leaning back in his chair and propping his feet up on the table.

"Damon." Stefan said, sitting across from him. "Orange doesn't suit you." The smirk fell from the others face.

"Not my choice. What do you want?"

"We need your help to catch Klaus Smith." Damon's eyes darkened and he sat up straight.

"What's in it for me?" He asked.

"What do you want?" Damon smirked.

"Out, obviously. And I want to be back in my loft, alone-"

"We'll have to keep surveillance on you." Stefan interrupted and nearly flinched under the power of Damon's glare. It reminded him of the rare looks their father would give him when he was upset with him. "My loft, my clothes...and I want to see Mom."

"Mine or yours?" The look on Damon's face made him regret saying that. "I'm sorry. I think we can do that." Stefan stood.

"Wait! There's one more thing!" Damon said, putting a hand on his shoulder. The guard in the room moved forward, and Stefan held up his hand. "It's the only thing I really want and without it, I won't help you."

"What?" Damon told him, and Stefan frowned.

"That will be more difficult. I'll call my boss and see what we can do."

Three days later, Damon Salvatore was sitting at an empty desk near his brother's, in his trademark black shirt, black jeans,

and black boots, toying with knife.

"Stef!" Tyler whispered, noticing it. "Should he have that?"

"Hey!" Damon said. "I'm not a killer."

"_Right_." Damon opened his mouth, but a woman's scream cut him off. Tyler and Stefan flinched at the sound, but Damon jumped up, a true smile gracing his face.

"Put me down!" The woman screamed. "I didn't do anything! Put me down!"

The two detectives jaws dropped when when two officers dropped a beautiful brunette to the ground.

"There you're down!" One said. "Now you stop screaming." He looked up and notice that Damon was starring at them, mad enough to kill. The scurried away quickly.

"What the hell?" The woman shouted, looking at Stefan and Tyler, not noticing Damon.

"Ladies don't talk that way, Katerina." Katherine looked up, and tears began to blur her vision.

"Damon?"

"Katherine." He said, softly. She got up and ran to him. He caught her, hiding his own tears in her curls.

"You're here." She whispered, breathing in his scent "You're really here."

"I am." He promised. "And I'm never leaving you again." He lifted her chin gently and kissed her. He looked at Stefan and Tyler and smiled at their shocked faces.

"Gentlemen, meet my wife, Katherine Peirce." Stefan stared at the woman who looked exactly like his fiance. She smiled timidly at them. "Now, I'd like to get back to my loft, boys."

"But you have to-"

"Tomorrow." Damon said. "But today is for her." Katherine smiled up at him.

"But-"

"He was in prison for three years, Stef." Tyler defended. "Give him a night. I'll go with them and take the first surveillance shift."

"Okay, but have to warn you. She's a screamer. Ow!" Damon doubled over, grabbing the place where Katherine had hit him hard in the stomach.

"Come on, Baby." She said, holding her hand out to him. Their fingers linked together as they walked away.

"Stefan, go home. Shave. Sleep. Spend some time with Elena, whatever. Just don't think about this case. I'll see you tomorrow." Tyler followed the couple out and Stefan sighed and gathered his things. He wouldn't be getting any work done until Damon was ready to cooperate.

He walked out of the station, dialing Elena's number.

* * *

><p><strong>I'm writing a very ooc Katherine this story, just a warning. 5 reviews to let me know if it's good?<strong>


	2. Chapter 2

Katherine laid her head on Damon's bare chest and tears filled her eyes at good it felt to be with him again. She hadn't held him like this for three years, and she died a little every time she woke up alone.

"Have you spoken to Klaus?" He asked, gently running his fingers through her curls.

"No, I haven't even seen him since you were sentenced. He sends money every month by one of his lackeys to pay for this place and to keep me entertained." She sat up and lit a cigarette. Damon raised an eyebrow at her. "What?"

"I thought you quit."

"I started again." She snapped defensively, then sighed. "Sorry, it's just...I've been going crazy without you." Damon sat up.

"I didn't kill those girls-" He started, but Katherine laid a gentle finger over his lips.

"I know, baby. I do. Klaus framed you."

"And we're going to take him down. But I'll need your help. You can't tell anyone I'm here, okay?" She nodded. He kissed her fingertips. "Then, when all this is over, I'm taking you out of this town. Anywhere you want." She took a drag of cigarette.

"And all the crime stuff is over? No more hacking or stealing?"

"Never again." She put the cigarette out and kissed him.

"I love you." Damon said when they broke apart. "Ever since the moment I met you."

Her mind went back five years ago to when she was seventeen. She'd snuck out with her friends and met Damon in a bar down town. He was three years older than her, smart, mysterious, and sexy. Her friends were jealous when he bought her drinks and asked her dance, and shocked when they got engaged only weeks later.

"I love you, too." She said, and pulled him on top of her. "Now make me scream like you told that detective I did." Damon laughed and eagerly fulfilled her request.

* * *

><p>Across town, Stefan Salvatore was explaining everything to his fiancee Elena Gilbert.<p>

"So...your older brother is a criminal and he's married to a woman who looks exactly like me?"

"Yes. I know it's a lot to take in, Elena."

"Do you?"

"Well, no." He sighed. "But I'm going to help you through this." Elena nodded and bit her lip.

"I know this isn't relevant, but I'm adopted... I don't know if I had twin sister, but..."

"It's possible."

"Is that all?" Stefan shook his head.

"There's one more thing and I doubt you'll like it." He sighed and ran his hands through his hair. Elena had been with him long enough to know that he only did that when he was nervous. "Klaus Smith is unpredictable, and if he finds out that Damon is helping us...he'll probably go ballistic."

"So?"

"So, starting tomorrow, you and Caroline will be staying with Katherine in Damon's loft with another officer watching you. It's only until we catch Klaus." He ended quickly, not liking the look on Elena's face. She smiled loving at him and kissed him.

"I'll do what I have to do. I knew what I was getting into when I said yes, Stefan. I knew something like this may happen one day." She kissed him again. "I love you."

"I love you, too." Elena took his hand and led him to their bedroom, losing clothes and stealing kisses along the way.

* * *

><p>"So there's a psycho killer after me?" Caroline Forbes panicked.<p>

"No, Care." Tyler said, leaning against Damon's door. "We're just taking precautions. I wanted to explain in person, but I'm kind of busy with work." He flinched as another high-pitched scream hit his ears from inside the apartment. How long could they go at it like that? Now he completely understood why the old woman that lived next door to them had made the face she did when she'd seen Damon.

"You're job is to stand guard while he's fucking a random girl?" Caroline laughed. Tyler smiled, know she was calmer.

"His wife actually. And get this, the criminal, Damon, is Stef's older brother-"

"Oh, my God!"

"That's not all. His wife, Katherine, looks _just like_ Elena. Like twins, Care." She was quite for a while.

"Oh, my God." She whispered.

"And you get to spend all day with them tomorrow."

"_Great_. Just _lovely_." She muttered. Tyler chuckled.

"I'll see tomorrow. I love you. Try to relax, I'm not going to let anything happen to you."

"I know. I love you too. And, Ty?"

"What?"

"Try not to lose your hearing." He hung up smiling.

* * *

><p>"I'll be back tonight." Damon promised and rolled his eyes. Katherine didn't believe that he wouldn't go after Klaus if he got a lead. But she dropped it and stood. Damon admired her body again, taking in the black lace boy shorts as she bent to pick up his shirt.<p>

"Are you hungry?" She asked, buttoning it. "I can make you something."

"You? Cook?" She frowned at his disbelieving tone.

"I took lessons, ass." She snapped, turning to leave. She gasped when his strong arms pulled her back against him.

"I would love something." He said gently. "I bet it's better than anything I could make."

"Never. You were born cooking." He kissed her neck and let her go. She walked to the front door, blissfully unaware of anything around her. She opened the door and Tyler woke up, pretending to be alert.

"Asleep on the job?" She asked. He looked ashamed and she smiled. "I won't tell. Would you like some coffee? Breakfast?"

"We don't have time to eat." He said, looking at his watch. "But I'll take some coffee." He followed her inside and she blushed when she noticed her and Damon's clothes laying in the floor.

"We didn't get a chance to...I'm sorry if we got a little loud last night."

"It's okay." He said. "I'll pretend it didn't happen." She smiled again and led him to the kitchen where Damon was looking at the paper.

"I didn't know we were having a guest." He said, not looking up.

"We are." He closed the paper and looked at her. She stared back as if they were having a mental conversation.

"Okay." He walked into another room and Katherine got the coffee ready.

"You can go with him. He's only going to watch TV."

"I don't know." Katherine met his eyes and he saw fire in them he didn't know existed in her. She seemed so sweet and slightly innocent.

''My husband is a good man, Detective Lockwood. He just...lost his way. But I can assure you, he's not a killer. He doesn't have it in him." Tyler nodded.

"I believe you. And please, Mrs. Salvatore, call me Tyler."

"Peirce. I kept my name." She said. "And please, call me Katherine. How do you take your coffee?"

"Black."

"Okay. Now shoo." He followed the path Damon took to the living room. Andi Starr was reporting the latest murder on the news.

"She's pretty hot, huh?" Damon gave him a look.

"You do know my wife's in the other room, right?"

"I was just saying." Damon looked at the blond on TV and shook his head.

"No. Not to me. But I don't think much of blonds." Tyler nodded. There was a long silence. "How long have you been a cop?"

"Couple years." He shrugged. "How long have you been...married?"

"About four years. But I only got to enjoy one, if you know what I mean."

"Shut up." Katherine said, putting their coffee down. Damon smirked and pulled her onto his lap and kissed her.

"I love you. I like to brag." She stroke his cheek.

"I love you, too. Now, shut up." Tyler laughed and Damon shoot him a cold look. Their was a knock on the door and Damon started to stand.

"Don't. It's pay day."

"Klaus?" Damon growled.

"Page boy. Go where you can't be seen. And hide your clothes." When he was gone she opened the door. "Elijah." She smiled.

"Hello, Katherine." He said, looking into the apartment. "Aren't you going to invite me in?"

"Not today. I'm not really up to company."

"Oh...Why?"

"Just thinking about Damon. I really miss him."

"We'll just remember, Klaus can provide any..._entertainment you_ might need."

"I have _that covered_." She took and thick envelope from him and closed the door. "He has a crush on me." She said.

"I'll kill him." Damon said coming back.

"Oh, relax. No other man has touched me since the wedding."

"What about your _entertainment_?" He growled. She put a soothing hand on his chest and got up close to him.

"Like I said, _I_ have _that covered_." Damon's eyebrows went up.

"Oh really?"

"It's time for us to go." Tyler said, feeling awkward. Damon kissed Katherine lingeringly.

"I'll be home tonight, love." She nodded.

"Another officer is here to watch you, just in case Klaus finds out we're working with Damon. And my girlfriend and Stefan's fiancee will be here soon."

"What?"

"It's easier if you're all together. I'm sorry I didn't tell you last night, but you locked me out."

"Okay. I'll get dressed and clean up." She kissed Damon again. "I'll see you tonight. Bye, Tyler." She disappeared into their bed room and the men left.


	3. Chapter 3

"What if she's a bitch?" Elena asked, as she and Caroline stopped outside the door of Damon and Katherine's apartment.

"Then we'll be bitches back. Calm down, Lena." Caroline knocked on the door.

"Coming!" A girls voice called.

"She was last night." Caroline snickered. The door opened and reveled Elena's mirror image.

"Whoa." She whispered, staring at her. "Um, please come in."

"Thanks." The three women stood awkwardly in the foyer of the loft.

"Coffee?" Katherine asked.

"Yes, please." Katherine led them to the kitchen and poured three cups. She put the milk and sugar on the counter and smiled.

"I'm Katherine Pierce, Damon's wife."

"I'm Caroline Forbes, Tyler Lockwood's girlfriend." Katherine nodded.

"I'm Elena." The straight haired brunette said. "Stefan Salvatore's fiancee." There was a long silence until Caroline broke.

"Okay, how do you two look exactly a like?" Both girls shrugged.

"I'm adopted." Elena said.

"So am I." Katherine said. "My parents told me they had a closed adoption and that when my birth mother gave birth they took me and never talked to her again. They died before I could get anymore details."

"My parents died, too." Elena whispered, the familiar pain rising in her chest.

"Well, we could always contact the hospital." Katherine said, leaning on the counter.

"I don't know..."

"Well this is just a messed up situation." Caroline said. "Possible- well, obvious.- twins, dating and married to known brother."

"Half brothers." Katherine said before she could stop herself. She blushed a little. "Different mothers."

"Do you have a picture of..."

"Damon? Of course. Just a second." She strutted up the stairs to the bedroom and Elena sighed.

"She's sex on legs Caroline." She groaned.

"She is pretty."

"She's gorgeous!"

"So are you!"

"But she knows how to it!"

"Here you go." Katherine said, coming back into the kitchen. She handed Caroline picture and she gasped.

"Wow. If he wasn't married..." Katherine laughed

"He looks nothing like Stefan." Elena whispered.

"He looks like his mother, I guess. I've never met her."

"Why not?" Katherine bit her lip and took the picture back.

"Because he's never met her. She up and left when he was born." She shook her head and smiled. "Would you like something to eat? I have plenty. Never stopped buying for two."

"Why was your husband in prison?" Caroline asked, hesitantly.

"He was framed. Damon is..._was_ a criminal- a hacker- but he was framed for the murder of three women. Damon couldn't...He's not..." Tears filled her eyes as she tried to find the right words to say.

"I'm sorry I asked. I didn't know it made you so upset."

"It's fine." She said, even though a few tears slipped down her cheeks. "It doesn't matter now." She smiled. "Let me fix you something. What would you like?"

"Anything's fine." Elena said.

"How about I order a pizza and we can watch a movie? Or we could go shopping!"

"Maybe next time?" Caroline said. "I haven't gotten paid yet."

"Me either."

"Oh, I've got!" Katherine said like they were silly children. She grabbed an envelope that she put all of Klaus's money in. "Klaus sends so much money every month, I don't think I'll ever spend it all. Just let me grab my bag. She walked back to her bedroom and Elena looked at Caroline.

"We can't let her do this."

"Sure we can. She's offering."

"Care-"

"Okay, let's go."

* * *

><p>"You have to get that." Katherine said. Elena jumped and dropped her hand from the red, silky material she was looking at.<p>

"I don't know..."

"I would if I knew Damon wouldn't tear it to shreds." Elena laughed a little.

"Stefan and I aren't really the lingerie type...We do it just to get it out of the way."

"Well that's not how sex should be, I should be ours of soft and slow and loving. Then a few more hours of Fast and rough-"

"Okay, I get it." Elena said. "Stefan's just not that..."

"Passionate?"

"Get that and come with me." Katherine said, picking up the same one in black. "I'll help you with that."

When the girls stopped for lunch, Caroline asked how Damon and Katherine met.

"When I was seventeen I found out I was adopted. I was so angry that they kept it from me for so long that I snuck out and went to a bar with my friends. When the bartender wouldn't buy my fake ID Damon bought me a drink. We danced, we flirted, and talked all night. We exchanged numbers and met up all the time. He asked me to marry him a month later, I said yes, and when I turned eighteen we went to Vegas. A few nights later he told me that Klaus had picked me for a target a few nights after we met. He knew the best way to protect me was to make me him. He told me he really did love me and we spent and incredible year together, then Klaus framed him."

"That's awful." Caroline whispered.

"Would you still have married him? If you knew?" Elena asked.

"Of course! I love him. He's so good to me. Good for me. He brings out a wilder side that I didn't know existed. And I bring out his gentle, loving side."

"Aw."

"What about you guys? Where'd you meet your boys?"

"High school." The two answered at the same time.

"Oh." Katherine said, sipping her Coke.

"Does it ever bother you that you got married so young?" Elena asked, twisting her engagment ring.

"No. I have everything I ever wanted. It's hard sometimes, but we manage."

"Elena's afraid of getting married."

"Don't be. It's like dating, but permanent. If you choose the right peron."

"What if you choose the wrong person?"

"You won't. Come on. Day's going to be home soon and I'm no where near done shopping." Katherine stood and led the way to the next store.


	4. Chapter 4

Later that night The girls and the officer that accompanied them piled into Katherine's red Mustang and drove back to her apartment building.

"We'll pay you back." Elena promised, hiding her Victoria's Secret bag so Caroline wouldn't see.

"No you won't. You two are my friends and I want to spoil you." Elena smiled and followed her upstairs.

"There you are!" Damon jumped up as they walked in.

"We went shopping."

"Did you get me anything?" Katherine held up her Victoria's Secret bag and Damon smirked.

"Yes!" He pulled her to his chest and kissed her.

"Meet Caroline and Elena." She said, wrapping her arms around his waist.

"Hi."

"Hi." The two girls said, awkwardly.

"I'm going to put these things away then I'll make dinner."

"Okay." They kissed again and Katherine went to the bedroom.

"They're in here." Damon said, leading the girls into the living room where Tyler and Stefan were watching a movie. Damon left them there to go help Katherine. Caroline playfully hit Tyler's arm.

"Why don't you ever help me hang up my clothes?"

"Because I'm not whipped." Caroline raised one eyebrow at him.

"Oh, really?"

"Do you guys want to stay for dinner?" Katherine asked, coming back in.

"Oh. Maybe next time." Caroline said, not meeting her eyes. Katherine's face fell a little, but she was smiled.

"I understand. Have a nice night." She led them to the door and Caroline and Tyler left quickly. Elena smiled at her mirror image.

"I had a lot of fun." She said, taking one of Katherine's hands in hers. "It was really great to meet you."

"You, too. Have a goodnight." Elena and Stefan left and Katherine closed the door and slid down it to sit on the floor, burring her hands in her face. Damon knelled down in front of her and pulled her hands away, wiping her tears away with his thumbs.

"What's wrong?"

"They don't like me." She whispered.

"I'm sure they do."

"Didn't you see how quickly they ran out? They hate me."

"I love you. That's all that matters."

"I love you too." She kissed him and sighed softly.

"Let's have dinner and I'll show you what I bought."

"Any black?"

"Of course." He smiled.

"Why don't we just hang out tonight? We haven't talked yet."

"What's there to talk about? All I've done is sit in this apartment for three years without my husband, waiting for him to be back in my arms."

"And now I am. But we do need to talk. About what were going to do after this."

"What do you mean?" Damon moved next to her and laid his head against the wall.

"Our future, Kat. Are we staying in Mystic Falls or leaving? If we leave where are going? Are we going to live in a house or and apartment? Do we want a dog? Kids? Do we-"

"You want kids?"

"I don't know. That's why we need to figure this out."

"Why? We're still so young. We have our whole lives ahead." Damon said nothing. "Day? What are you thinking?"

"We're going against Klaus, Katherine." He said, closing his eyes. "I don't know if-"

"Don't say it. Don't even think it!"

"It could happen. We might not have forever and-"

"So you're trying make future plans with me? What if you did get killed? What I do, Damon?"

"You'd move on!"

"I can't believe you." She whispered.

"Kat-"

"Sleep down here tonight." She stood and started toward the stairs, leaving Damon on the ground.

"Katherine!"

"Goodnight Damon."

A few hours later Damon was woken from his sleep by a gentle hand. Katherine stood before him in a short black silk night gown.

"Come to bed." She whispered. He nodded and linked their fingers together, following her to their bedroom.

* * *

><p>"How was your day?" Stefan called to Elena who was in the bathroom, biting her lip over her pajamas or the nightgown Katherine bought her.<p>

"Good. How was yours."

"Damon's still a pain, but we got some good information out of him."

"That's good." We'll get more out of him tomorrow. He thinks he knows where Klaus is hiding out." Elena picked up her pajamas and pulled them on. She knew nothing was going to happen tonight. It never did if something was going to happen at work the next day. She twisted her engagement ring around her finger.

"That's amazing." She said, coming into the bedroom.

"Yeah." Stefan agreed. "It's pretty great." She crawled into bed and cuddled against him.

"I love you, Stefan."

"I love you, too." He murmured, sleepily. She closed her eyes, hoping the rest of their time together wouldn't always be like this.

* * *

><p>"Do you think I was mean?" Caroline asked Tyler while they watching old Friends reruns.<p>

"When?"

"When I told Katherine no about dinner. I mean, it's not like she has a lot of friends, she's locked herself in that apartment for years. She's just so nice, I'd hate to hurt her feelings."

"I'm sure it's okay."

"Did you see her face? She looked crushed." Tyler sighed and turned the television off.

"I'm sure it's fine." He repeated. "She was probably just being nice. The way Damon talks, they love to be alone together."

"But if she was seriously offering-"

"Just invite them over sometime then!"

"Are you okay." Tyler sighed.

"Yeah. Sorry. It's just this case. It's wearing us all out."

"Do you just want to go to bed? Rest up for tomorrow?"

"That'd be great." They changed for bed and curled up together.

"I love you." Caroline said, pressing a soft kiss to his chest.

"Love you, too." He whispered, before dozing off.

* * *

><p>"She seemed upset today." Elijah said, looking out the window at the stars. "Lonely." An evil smile spread across Klaus's face.<p>

"Exactly what I want." Elijah shook his head.

"She loves her husband, Klaus. She belongs to him. She has ever since-"

"Silence. Katerina will be mine. And i won't let anyone else have her. Especially not _Damon Salvatore_."

"Why do you hate him? In all our interactions he seemed like a nice man."

"Nice or not, he has what I want."

Elijah sighed and walked out of his brother's room. He, too, wanted Katerina, but he knew how much she loved her husband.

For the past three years he'd seen her after sleepless nights full of tears, heard her voice break when spoke of Damon.

'_I have to let her know what Klaus is up to_.' He thought. '_Perhaps she won't be too angry with me..._' But when he thought of Klaus's wrath, it just wasn't worth it.

She was still young and would get tired of sitting home alone eventually. He'd have her then.

* * *

><p><strong>5 reviews to next chapter<strong>


End file.
